Solid-state imaging device, manufacturing method for the same, and imaging apparatus

ABSTRACT

A solid-state imaging device includes: a pixel section including, in a semiconductor substrate, plural photoelectric conversion sections that photoelectrically convert incident light to generate signal charges; metal wirings formed, on a first insulating film formed on the semiconductor substrate, above regions among the photoelectric conversion sections and above the periphery of the pixel section; a second insulating film formed on the first insulating film to cover the metal wirings; a first light shielding film formed on the second insulating film and having an opening above the pixel section; and a second light shielding film formed above the metal wirings above the pixel section and having thickness smaller than that of the first light shielding film.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present invention is a Divisional application of U.S. patentapplication Ser. No. 12/379,336, filed Feb. 19, 2009, and containssubject matter related to Japanese Patent Application JP 2008-060630filed in the Japanese Patent Office on Mar. 11, 2008, the entirecontents of which being incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state imaging device, amanufacturing method for the same, and an imaging apparatus.

2. Description of the Related Art

A solid-state imaging device in the past includes a photoelectricconversion region formed in a semiconductor substrate, signal readingout means for reading out signal charges generated in the photoelectricconversion region, and a metal light shielding film that is formed onthe semiconductor substrate via an insulating film and has an opening onthe photoelectric conversion region. The metal light shielding film isformed of, for example, aluminum.

When oblique incident light is made incident on the photoelectricconversion region of the solid-state imaging device having suchstructure, the incident light is reflected on an end face and a surfaceof the light shielding film and made incident on an element differentfrom a photoelectric conversion section that should originally receivethe light. This incident light is photoelectrically converted into afalse signal charge in a photoelectric conversion section different fromthe photoelectric conversion section on which the light shouldoriginally be made incident.

In order to solve the problem, in some solid-state imaging devices, ablack dyed layer (see, for example, JP-A-4-337667), black insulativeresin (see, for example, JP-A-1-191481), and a black color resist inwhich pigment, carbon black, or the like is included (see, for example,JP-A-7-86545) are used as light shielding films instead of the metallight shielding film.

When the periphery of the photoelectric conversion sections is shieldedfrom light by using the black insulative resin or the like, thethickness equal to or larger than 1 is necessary to suppress flare lightdue to metal wirings in a large area.

For example, when a light shielding film made of one layer of the blackinsulative resin is formed not only in the periphery of a pixel regionhaving plural photoelectric conversion sections but also among thephotoelectric conversion sections, a light shielding film as high asabout 1 μm is formed among the photoelectric conversion sections as inthe periphery of the pixel region.

Therefore, a part of oblique incident light about to be made incident onthe photoelectric conversion sections is blocked by the light shieldingfilm formed among the photoelectric conversion sections. This is a causeof a fall in the sensitivity of the solid-state imaging device.

SUMMARY OF THE INVENTION

The present invention addresses a problem in that, when a lightshielding film around an opening formed above a pixel and a lightshielding film formed above regions among photoelectric conversionsections in the pixel are formed in the same thickness in order tosuppress flare light, a part of oblique incident light on thephotoelectric conversion sections is blocked and sensitivity falls.

Therefore, it is desirable to simultaneously realize both thesuppression of the flare light and the prevention of the fall insensitivity.

According to an embodiment of the present invention, there is provided asolid-state imaging device including:

a pixel section including, in a semiconductor substrate, pluralphotoelectric conversion sections that photoelectrically convertincident light to generate signal charges;

metal wirings formed, on a first insulating film formed on thesemiconductor substrate, above regions among the photoelectricconversion sections and above the periphery of the pixel section;

a second insulating film formed on the first insulating film to coverthe metal wirings;

a first light shielding film formed on the second insulating film andhaving an opening above the pixel section; and

a second light shielding film formed above the metal wirings above thepixel section and having thickness smaller than that of the first lightshielding film.

In the solid-state imaging device according to the embodiment, the firstlight shielding film can be formed in the thickness equal to or largerthan 1 win order to suppress flare light due to the metal wirings in alarge area. Even if the first light shielding film is formed in suchthickness, the second light shielding film formed above the metalwirings above the pixel section is formed in the thickness smaller thanthat of the first light shielding film. Therefore, a part of obliqueincident light about to be made incident on the photoelectric conversionsections, which is blocked by the light shielding film having thethickness in the past, i.e., the light shielding film having thethickness equal to the thickness of the first light shielding film, canbe made incident on the photoelectric conversion sections.

Further, since the second light shielding film is formed above regionsamong the photoelectric conversion sections in the opening, flare lightis suppressed.

According to another embodiment of the present invention, there isprovided a manufacturing method (a first manufacturing method) for asolid-state imaging device including the steps of:

forming, on a first insulating film that covers a pixel section havingplural photoelectric conversion sections that are formed in asemiconductor substrate and photoelectrically convert incident light togenerate signal charges, metal wirings above regions among thephotoelectric conversion sections and above the periphery of the pixelsection;

forming a first light shielding film via a second insulating film thatcovers the metal wirings;

forming an opening in the first light shielding film above the pixelsection;

forming a second light shielding film that has thickness smaller thanthat of the first light shielding film on the first light shielding filmincluding the opening; and

removing, while leaving the second light shielding film on the secondinsulating film above the metal wirings above the pixel section, thesecond light shielding film formed in other regions.

In the manufacturing method (the first manufacturing method) for asolid-state imaging device according to the embodiment, the first lightshielding film can be formed in the thickness equal to or larger than 1win order to suppress flare light due to the metal wirings in a largearea. Even if the first light shielding film is formed in suchthickness, the second light shielding film formed above the metalwirings above the pixel section is formed in the thickness smaller thanthat of the first light shielding film. Therefore, a part of obliqueincident light about to be made incident on the photoelectric conversionsections, which is blocked by the light shielding film having thethickness in the past, i.e., the light shielding film having thethickness equal to the thickness of the first light shielding film, canbe made incident on the photoelectric conversion sections.

Further, since the second light shielding film is formed above regionsamong the photoelectric conversion sections in the opening, flare lightis suppressed.

According to still another embodiment of the present invention, there isprovided a manufacturing method (a second manufacturing method) for asolid-state imaging device including the steps of:

forming, on a first insulating film that covers a pixel section havingplural photoelectric conversion sections that are formed in asemiconductor substrate and photoelectrically convert incident light togenerate signal charges, metal wirings above regions among thephotoelectric conversion sections and above the periphery of the pixelsection;

forming a second light shielding film via a second insulating film thatcovers the metal wirings;

removing, while leaving the second light shielding film on the secondinsulating film above the metal wirings above the pixel section, thesecond light shielding film formed in other regions;

forming, on the second insulating film, a first light shielding filmthat covers the second light shielding film and has thickness largerthan that of the second light shielding film; and

forming an opening in the first light shielding film above the pixelsection.

In the manufacturing method (the second manufacturing method) for asolid-state imaging device according to the embodiment, the first lightshielding film can be formed in the thickness equal to or larger than 1μm in order to suppress flare light due to the metal wirings in a largearea. Even if the first light shielding film is formed in suchthickness, the second light shielding film formed above the metalwirings above the pixel section is formed in the thickness smaller thanthat of the first light shielding film. Therefore, a part of obliqueincident light about to be made incident on the photoelectric conversionsections, which is blocked by the light shielding film having thethickness in the past, i.e., the light shielding film having thethickness equal to the thickness of the first light shielding film, canbe made incident on the photoelectric conversion sections.

Further, since the second light shielding film is formed above regionsamong the photoelectric conversion sections in the opening, flare lightis suppressed.

According to still another embodiment of the present invention, there isprovided a manufacturing method (a third manufacturing method) for asolid-state imaging device including the steps of:

forming, on a first insulating film that covers a pixel section havingplural photoelectric conversion sections that are formed in asemiconductor substrate and photoelectrically convert incident light togenerate signal charges, metal wirings above regions among thephotoelectric conversion sections and above the periphery of the pixelsection;

forming a second light shielding film via a second insulating film thatcovers the metal wirings;

removing, while leaving the second light shielding film above the metalwirings above the pixel section, the remaining second light shieldingfilm above the pixel section to form an opening;

forming, on the second insulating film, a first light shielding filmthat covers the second light shielding film; and

forming an opening in the first light shielding film above the pixelsection.

In the manufacturing method (the third manufacturing method) for asolid-state imaging device according to the embodiment, a lightshielding film formed by combining the first light shielding film andthe second light shielding film can be formed in the thickness equal toor larger than 1 μm in order to suppress flare light due to the metalwirings in a large area. Even if the light shielding film is formed insuch thickness, the second light shielding film formed above the metalwirings above the pixel section is formed in the thickness smaller thanthat of the light shielding film. Therefore, a part of oblique incidentlight about to be made incident on the photoelectric conversionsections, which is blocked by the light shielding film having thethickness in the past, i.e., the light shielding film having thethickness equal to the thickness of the first light shielding film, canbe made incident on the photoelectric conversion sections.

Further, since the second light shielding film is formed above regionsamong the photoelectric conversion sections in the opening, flare lightis suppressed.

According to still another embodiment of the present invention, there isprovided an imaging apparatus including:

a condensing optical unit that condenses incident light;

a solid-state imaging device that receives the light condensed by thecondensing optical unit and photoelectrically converts the light; and

a signal processing unit that processes the photoelectrically-convertedsignal, wherein

the solid-state imaging device includes:

-   -   a pixel section including, in a semiconductor substrate, plural        photoelectric conversion sections that photoelectrically convert        incident light to generate signal charges;    -   metal wirings formed, on a first insulating film formed on the        semiconductor substrate, above regions among the photoelectric        conversion sections and above the periphery of the pixel        section;    -   a second insulating film formed on the first insulating film to        cover the metal wirings;    -   a first light shielding film formed on the second insulating        film and having an opening above the pixel section; and    -   a second light shielding film formed above the metal wirings        above the pixel section and having thickness smaller than that        of the first light shielding film.

In the imaging apparatus according to the embodiment, since thesolid-state imaging device according to the embodiment explained aboveis used, apart of oblique incident light about to be made incident onthe photoelectric conversion sections, which is blocked by the lightshielding film in the past, can be made incident on the photoelectricconversion sections.

Further, since the second light shielding film is formed above regionsamong the photoelectric conversion sections in the opening, flare lightis suppressed.

Since the solid-state imaging device according to the embodimentincludes the first light shielding film that has the opening above thepixel section and the second light shielding film that is formed abovethe metal wirings above the pixel section and has thickness smaller thanthat of the first light shielding film, it is possible to simultaneouslyrealize both the suppression of flare light and the prevention of a fallin sensitivity. Therefore, there is an advantage that it is possible torealize improvement of an image quality of the solid-state imagingdevice.

In the first manufacturing method for a solid state imaging deviceaccording to the embodiment, since the first light shielding film thathas the opening above the pixel section is formed and the second lightshielding film that has thickness smaller than that of the first lightshielding film is formed above the metal wirings above the pixelsection, it is possible to simultaneously realize both the suppressionof flare light and the prevention of a fall in sensitivity. Therefore,there is an advantage that it is possible to realize improvement of animage quality of the solid-state imaging device.

In the second manufacturing method for a solid state imaging deviceaccording to the embodiment, since the first light shielding film thathas the opening above the pixel section is formed and the second lightshielding film that has thickness smaller than that of the first lightshielding film is formed above the metal wirings above the pixelsection, it is possible to simultaneously realize both the suppressionof flare light and the prevention of a fall in sensitivity. Therefore,there is an advantage that it is possible to realize improvement of animage quality of the solid-state imaging device.

In the third manufacturing method for a solid state imaging deviceaccording to the embodiment, since the first light shielding film andthe second light shielding film that have the openings above the pixelsection are formed and the second light shielding film is left above themetal wirings above the pixel section, it is possible to simultaneouslyrealize both the suppression of flare light and the prevention of a fallin sensitivity. Therefore, there is an advantage that it is possible torealize improvement of an image quality of the solid-state imagingdevice.

In the imaging apparatus according to the embodiment, since thesolid-state imaging device according to the embodiment explained aboveis used, it is possible to simultaneously realize both the suppressionof flare light and the prevention of a fall in sensitivity. Therefore,there is an advantage that it is possible to realize improvement of animage quality of the solid-state imaging device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of a solid-state imaging deviceaccording to an embodiment (a first embodiment) of the presentinvention;

FIG. 2 is a schematic sectional view of a problem of peeling of a lightshielding film in the past;

FIG. 3 is a graph of a relation between the minimum line width and thethickness of a light shielding film;

FIG. 4 is a schematic sectional view of a solid-state imaging deviceaccording to an embodiment (a second embodiment) of the presentinvention;

FIG. 5 is a schematic sectional view of a solid-state imaging deviceaccording to an embodiment (a third embodiment) of the presentinvention;

FIGS. 6A to 6D show sectional views of manufacturing steps of amanufacturing method for a solid-state imaging device according to thefirst embodiment;

FIGS. 7A to 7D show sectional views of manufacturing steps of amanufacturing method for a solid-state imaging device according to thesecond embodiment;

FIGS. 8A to 8D show sectional views of manufacturing steps of amanufacturing method for a solid-state imaging device according to thethird embodiment; and

FIG. 9 is a block diagram of an imaging apparatus according to anembodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A solid-state imaging device according to an embodiment (a firstembodiment) of the present invention is explained with reference to aschematic sectional view in FIG. 1.

As shown in FIG. 1, a pixel section 12 is formed in a semiconductorsubstrate 11. In the pixel section 12, plural photoelectric conversionsections 13 that photoelectrically convert incident light are formed.Although not shown in the figure, in the semiconductor substrate 11, areadout section for reading out signal charges from the photoelectricconversion sections 13 and a charge transfer section for transferringthe signal charges read out by the readout section are formed on oneside of the photoelectric conversion sections 13. A channel stop regionfor pixel separation is formed on the other side of the photoelectricconversion sections 13.

An integrated circuit (not shown) for driving the solid-state imagingdevice is formed around the photoelectric conversion sections 13.Large-pattern metal wirings 22 (22L) are arranged above the integratedcircuit, which causes malfunction because of incident of light, toprevent the malfunction.

A first insulating film 21 that covers a transfer electrode (not shown)formed in the charge transfer section is formed on the semiconductorsubstrate 11. The metal wirings 22 are formed on the first insulatingfilm 21. A second insulating film 23 that covers the metal wirings 22 isformed on the first insulating film 21. The second insulating film 23 isformed of a silicon nitride film, a silicon oxide nitride film, of asilicon oxide film. More preferably, the silicon nitride film is used.Moisture from a light shielding film 31 formed on the second insulatingfilm 23 can be prevented from penetrating the photoelectric conversionsections 13 by forming the second insulating film 23 with an inorganicinsulating film such as the silicon nitride film. The light shieldingfilm 31 that covers the metal wirings 22 is formed on the secondinsulating film 23.

The light shielding film 31 includes a first light shielding film 33that is formed on the second insulating film 23 and has an opening 32above the pixel section 12. Further, the light shielding film 31includes a second light shielding film 34 that is formed above the metalwirings 22 above the pixel section 12 in the opening 32 and hasthickness smaller than that of the first light shielding film 33.

The opening 32 means a space, a side periphery of which is surrounded bya sidewall of the first light shielding film 33 on the pixel section 12.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of black orblackish photosensitive insulative resin. Consequently, reflection ofthe light shielding films is suppressed. Moreover, it is unnecessary toform a resist mask for the patterning. In other words, there is anadvantage that the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

In the light shielding film of the solid-state imaging device 1, thefirst light shielding film 33 formed of the black insulative resinpatterned by the lithography method attenuates light reflected on themetal wirings 22 in a large area present in regions other than above aregion where the plural photoelectric conversion sections are formed.

For the first light shielding film 33, it is necessary to selectthickness for suppressing an amount of light reflected on the metalwirings 22 in the large area to be equal to or smaller than a fixedamount. For example, thickness equal to or larger than 1.0 μm isnecessary.

The black color resist is usually a negative resist and has a highattenuation ratio with respect to exposure light used for thepatterning. Therefore, as shown in FIG. 2, when a light shielding film131 is formed of a black color resist having the thickness of about 1.0μm above regions among photoelectric conversion sections 113 (equivalentto the photoelectric conversion sections 13 according to thisembodiment) of a pixel section 112, a sectional shape of the lightshielding film 131 is an undercut shape. When a pattern of the lightshielding film 131 is fine, a grounding area of the pattern is small.Therefore, pattern peeling occurs.

The refining of the pattern of the light shielding film 131 formed aboveregions among the photoelectric conversion sections 113 is in aconflicting relation with the thickness of the light shielding film 131and a flare prevention effect. For example, a relation between theminimum line width and the thickness of the light shielding film 131 isshown in FIG. 3.

As shown in FIG. 3, the minimum line width and the thickness of thelight shielding film 131 are in a proportional relation. Therefore, asthe thickness of the light shielding film 131 increases, the minimumline width that can be formed by the light shielding film 131 alsoincreases. The flare prevention effect is improved as the thickness ofthe light shielding film 131 increases.

Therefore, as indicated by FIG. 1, in narrow regions like the regionsamong the photoelectric conversion sections 13, the line width of thesecond light shielding film 34 formed above the metal wirings 22 abovethe pixel section 12 is formed small. Therefore, since it is difficultto form the light shielding film 34 as thick as, for example, 1.0 μmlike the first light shielding film 33, it is necessary to form thesecond light shielding film 34 in thickness smaller than that of thefirst light shielding film 33 and, accordingly, an attenuation ratio offlare light decreases.

However, concerning the decrease in the attenuation ratio of flarelight, since an area of metal wirings is small, it is possible tosuppress an amount of the flare light to be equal to or smaller than afixed amount.

Therefore, in this embodiment, the second light shielding film 34 abovethe metal wirings 22 above the pixel section 12 is formed in thicknesssmaller than that of the first light shielding film 33 to make itpossible to secure adhesion with a substrate even if undercut occurs ina sectional shape and the second light shielding film 34 is formed in aso-called reverse taper shape. For example, the thickness of the firstlight shielding film 33 is set to 1.0 μm and the thickness of the secondlight shielding film 34 is set to 0.5 μm. In this way, the thickness ofthe second light shielding film 34 is set smaller than that of the firstlight shielding film 33. Consequently, an area of grounding with thesubstrate is twice as large as that of the second light shielding film34 formed in thickness equal to that of the first light shielding film33 as in the past. As a result, since peeling of the second lightshielding film 34 is prevented, it is possible to improve the flareprevention effect in the entire solid-stage imaging device 1.

It is also possible to improve the flare prevention effect by increasingthe width of the second light shielding film 34 such that a pattern canbe formed in single thickness. However, since a part of oblique incidentlight is blocked, a fall in sensitivity due to a reduction in an openingarea of the photoelectric conversion sections 13 poses a problem. Sincethe second light shielding film 34 provided above the metal wirings 22above the pixel section 12 is formed in thickness smaller than that ofthe first light shielding film 33 provided around the pixel region, atleast a part of the oblique incident light penetrates the photoelectricconversion sections 13. Consequently, since an amount of incident lighton the photoelectric conversion sections 13 increases, improvement ofthe sensitivity of the solid-state imaging device can be realized.

In short, in the solid-state imaging device 1, the first light shieldingfilm 33 can be formed in the thickness equal to or larger than 1 μm inorder to suppress the flare light due to the metal wirings in the largearea. Even if the first light shielding film 33 is formed in suchthickness, the second light shielding film 34 formed above the metalwirings 22 above the pixel section 12 in the opening 32 is formed inthickness smaller than that of the first light shielding film 33.Therefore, a part of the oblique incident light about to be madeincident on the photoelectric conversion sections 13, which is blockedby the light shielding film having the thickness in the past, i.e., thelight shielding film having film thickness equal to the thickness of thefirst light shielding film 33, can be made incident on the photoelectricconversion sections 13.

Since the second light shielding film 34 is formed above in the regionsabove the photoelectric conversion sections 33 in the opening 32, flarelight is suppressed.

In this way, with the solid-state imaging device 1 according to thisembodiment, it is possible to solve the problem of peeling of the lightshielding film 31 (the second light shielding film 34) and reduce flarelight.

Therefore, there is an advantage that it is possible to obtain asolid-state imaging device excellent in an image quality with flarelight reduced.

A solid-state imaging device according to an embodiment (a secondembodiment) of the present invention is explained with reference to aschematic sectional view in FIG. 4. A solid-state imaging device 2according to the second embodiment is a solid-state imaging devicemounted with a color filter in addition to the components of thesolid-state imaging device 1.

As shown in FIG. 4, the pixel section 12 is formed in the semiconductorsubstrate 11. In the pixel section 12, the plural photoelectricconversion sections 13 that photoelectrically convert incident light areformed. Although not shown in the figure, in the semiconductor substrate11, a readout section for reading out signal charges from thephotoelectric conversion sections 13 and a charge transfer section fortransferring the signal charges read out by the readout section areformed on one side of the photoelectric conversion sections 13. Achannel stop region for pixel separation is formed on the other side ofthe photoelectric conversion sections 13.

An integrated circuit (not shown) for driving the solid-state imagingdevice is formed around the photoelectric conversion sections 13. Thelarge-pattern metal wirings 22 (22L) are arranged above the integratedcircuit, which causes malfunction because of incident of light, toprevent the malfunction.

The first insulating film 21 that covers a transfer electrode (notshown) formed in the charge transfer section is formed on thesemiconductor substrate 11. The metal wirings 22 are formed on the firstinsulating film 21. The second insulating film 23 that covers the metalwirings 22 is formed on the first insulating film 21. The secondinsulating film 23 is formed of a silicon nitride film, a silicon oxidenitride film, of a silicon oxide film. More preferably, the siliconnitride film is used. Moisture from a color filter layer 41 and thelight shielding film 31 formed on the second insulating film 23 can beprevented from penetrating the photoelectric conversion sections 13 byforming the second insulating film 23 with an inorganic insulating filmsuch as the silicon nitride film.

A desired color filter layer 41 is formed on the second insulating film23 in association with positions above the photoelectric conversionsections 13. The color filter layer 41 is formed by, for example, colorfilter layers 41A and 41B of predetermined colors in association withthe photoelectric conversion sections 13, respectively. For example, thecolor filter layer 41 may be formed by a color filter layer for red, acolor filter layer for green, and a color filter layer for blue. It goeswithout saying that color filter layers for complementary colors may beused and color filer layers for colors other than the colors describedabove may be used. A third insulating film 25 is formed on the colorfilter layer 41.

Color resists are left in order to planarize regions other than a regionabove the pixel section 12. Actually, since unevenness occurs amongdifferent color resists, the third insulating film 25 made oftransparent resin is formed in order to planarize steps among the colorresists.

The light shielding film 31 that covers the metal wirings 22 is formedon the third insulating film 25.

The light shielding film 31 includes the first light shielding film 33that is formed on the second insulating film 23 and in which the opening32 is formed above the pixel section 12. Further, the light shieldingfilm 31 includes the second light shielding film 34 that is formed abovethe metal wirings 22 above the pixel section 12 in the opening 32 andhas thickness smaller than that of the first light shielding film 33.

The opening 32 means a space, a side periphery of which is surrounded bythe sidewall of the first light shielding film 33 on the pixel section12.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of blackphotosensitive insulative resin. Consequently, reflection of the lightshielding films is suppressed. Moreover, it is unnecessary to form aresist mask for the patterning. In other words, there is an advantagethat the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

In the solid-state imaging device 2, actions and effects same as thosein the solid-state imaging device 1 are obtained.

A solid-state imaging device according to an embodiment (a thirdembodiment) of the present invention is explained with reference to aschematic sectional view in FIG. 5. A solid-state imaging device 3according to the third embodiment is a solid-state imaging devicemounted with a color filter in addition to the components of thesolid-state imaging device 1.

As shown in FIG. 5, the pixel section 12 is formed in the semiconductorsubstrate 11. In the pixel section 12, the plural photoelectricconversion sections 13 that photoelectrically convert incident light areformed in the pixel section 12. Although not shown in the figure, in thesemiconductor substrate 11, a readout section for reading out signalcharges from the photoelectric conversion sections 13 and a chargetransfer section for transferring the signal charges read out by thereadout section are formed on one side of the photoelectric conversionsections 13. A channel stop region for pixel separation is formed on theother side of the photoelectric conversion sections 13.

An integrated circuit (not shown) for driving the solid-state imagingdevice is formed around the photoelectric conversion sections 13. Thelarge-pattern metal wirings 22 (22L) are arranged above the integratedcircuit, which causes malfunction because of incident of light, toprevent the malfunction.

The first insulating film 21 that covers a transfer electrode (notshown) formed in the charge transfer section is formed on thesemiconductor substrate 11. The metal wirings 22 are formed on the firstinsulating film 21. The second insulating film 23 that covers the metalwirings 22 is formed on the first insulating film 21.

The second insulating film 23 is formed of a silicon nitride film, asilicon oxide nitride film, of a silicon oxide film. More preferably,the silicon nitride film is used. Moisture from the light shielding film31 and the color filter layer 41 formed on the second insulating film 23can be prevented from penetrating the photoelectric conversion sections13 by forming the second insulating film 23 with an inorganic insulatingfilm such as the silicon nitride film.

The light shielding film 31 that covers the metal wirings 22 is formedon the second insulating film 23.

The light shielding film 31 includes the first light shielding film 33that is formed on the second insulating film 23 and has the opening 32above the pixel section 12. Further, the light shielding film 31includes the second light shielding film 34 that is formed above themetal wirings 22 above the pixel section 12 in the opening 32 and hasthickness smaller than that of the first light shielding film 33.

The opening 32 means a space, a side periphery of which is surrounded bythe sidewall of the first light shielding film 33 on the pixel section12.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of blackphotosensitive insulative resin. Consequently, reflection of the lightshielding films is suppressed. Moreover, it is unnecessary to form aresist mask for the patterning. In other words, there is an advantagethat the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

The desired color filter layer 41 is formed on the second insulatingfilm 23 in association with positions above the photoelectric conversionsections 13. The color filter layer 41 is formed in the second lightshielding film 34 in the opening 32 formed in the first light shieldingfilm 33. The color filter layer 41 is formed by, for example, the colorfilter layers 41A and 41B of predetermined colors in association withthe photoelectric conversion sections 13, respectively. For example, thecolor filter layer 41 is formed by a color filter layer for red, a colorfilter layer for green, and a color filter layer for blue. It goeswithout saying that color filter layers for complementary colors may beused and color filer layers for colors other than the colors describedabove may be used.

The solid-state imaging device 1 explained with reference to FIG. 2 is asolid-state imaging device for a three plate system (3CCD) image sensoror an image sensor for white and black images. The solid-state imagingdevices 2 and 3 explained with reference to FIGS. 4 and 5 can be usedfor a color solid-state imaging device and can also be used for a singleplate system color imaging device by limiting types of color filters.

In the solid-state imaging device 3, actions and effects same as thosein the solid-state imaging device 1 are obtained.

A manufacturing method for the solid-state imaging device according tothe first embodiment is explained with reference to sectional views ofmanufacturing steps in FIGS. 6A to 6D.

As shown in FIG. 6A, the pixel section 12 is formed in the semiconductorsubstrate 11. In the pixel section 12, the plural photoelectricconversion sections 13 that photoelectrically convert incident light togenerate signal charges are formed. Although not shown in the figure, inthe semiconductor substrate 11, a readout section for reading out signalcharges from the photoelectric conversion sections 13 and a chargetransfer section for transferring the signal charges read out by thereadout section are formed on one side of the photoelectric conversionsections 13. A channel stop region for pixel separation is formed on theother side of the photoelectric conversion sections 13.

The first insulating film 21 that covers a transfer electrode (notshown) formed in the charge transfer section is formed on thesemiconductor substrate 11. The metal wirings 22 are formed on the firstinsulating film 21. The second insulating film 23 that covers the metalwirings 22 is formed on the first insulating film 21.

The second insulating film 23 is formed of a silicon nitride film, asilicon oxide nitride film, of a silicon oxide film. More preferably,the silicon nitride film is used. Moisture from the light shielding film31 formed on the second insulating film 23 can be prevented frompenetrating the photoelectric conversion sections 13 by forming thesecond insulating film 23 with an inorganic insulating film such as thesilicon nitride film.

The light shielding film 31 is formed on the second insulating film 23.The light shielding film 31 is formed as explained below.

First, the first light shielding film 33 is formed on the secondinsulating film 23. The first light shielding film 33 is formed of ablack photoresist in, for example, thickness equal to or larger than 1.0μm. A material of the first light shielding film 33 is explained indetail later.

The black color resist is a negative resist. Since exposure lightattenuates in the black color resist, the black color resist has anundercut sectional shape. Therefore, for example, a pattern having, forexample, pattern dimension width equal to or smaller than 1.5 μm has areduced area of grounding with a substrate and pattern peeling occurs.Therefore, it is desirable to eliminate such a pattern from a mask.

Subsequently, as shown in FIG. 6B, the first light shielding film 33 issubjected to exposure to light, development, and baking to form theopening 32 above the pixel section 12.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

The opening 32 means a space, a side periphery of which is surrounded bya sidewall of the first light shielding film 33 on the pixel section 12.

As shown in FIG. 6C, the second light shielding film 34 having thicknesssmaller than that of the first light shielding film 33 is formed overthe entire surface in the opening 32 formed in the first light shieldingfilm 33. The second light shielding film 34 is formed of a blackphotoresist in, for example, the thickness of 0.5%. A material of thesecond light shielding film 34 is explained in detail later.

As shown in FIG. 6D, the second light shielding film 34 is subjected toexposure to light, development, and baking to leave the second lightshielding film 34 above the metal wirings 22 (22S) above the pixelsection 12 in the opening 32 and remove the second light shielding film34 in the other regions. As a result, the second light shielding film 34is formed above the metal wirings 22S above the pixel section 12 in theopening 32.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

When the second light shielding film 34 is patterned, since the firstlight shielding film 33 is cured by baking, a pattern shape ismaintained even if exposure, development, and the like is applied to thesecond light shielding film 34.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of blackphotosensitive insulative resin. Consequently, reflection of the lightshielding films is suppressed. Moreover, it is unnecessary to form aresist mask for the patterning. In other words, there is an advantagethat the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

In the first manufacturing method, the first light shielding film 33 canbe formed in the thickness equal to or larger than 1 μm. Therefore,since light reflected on the large-area metal wirings 22L other thanregions where the photoelectric conversion sections 13 are formed isattenuated, flare light can be suppressed.

Even if the first light shielding film 33 is formed in such thicknessequal to or larger than 1 μm, the second light shielding film 34 formedabove the metal wirings 22 above the pixel section 12 in the opening 32is formed in thickness smaller than that of the first light shieldingfilm 33, for example, the thickness of 0.5 μm. Therefore, a part of theoblique incident light about to be made incident on the photoelectricconversion sections 13, which is blocked by the light shielding filmhaving the thickness in the past, i.e., the light shielding film havingfilm thickness equal to the thickness of the first light shielding film33, can be made incident on the photoelectric conversion sections 13.

Consequently, since an amount of incident light on the photoelectricconversion sections 13 increases, improvement of the sensitivity of thesolid-state imaging device can be realized.

Moreover, since the second light shielding film 34 is formed above themetal wirings 22 above the pixel section 12, the second light shieldingfilm 34 has so-called submicron line width (e.g., equal to or smallerthan 1.5 μm). However, the thickness of the second light shielding film34 is smaller than the thickness of the first light shielding film 34,for example, 1.0 μm and is 0.5 μm in the example explained above.Therefore, even if undercut occurs in the second light shielding film 34in the exposure and development steps and a sectional shape thereofchanges to a so-called reverse taper shape, since an area of groundingwith the second insulating film 23 as the substrate is sufficientlysecured, the problem of peeling is solved.

Since the second light shielding layer 34 is formed above the metalwirings 22 above the pixel section 12 in the opening 32, the metalwirings 22 above the pixel section 12 can be shielded from light. Thismakes it possible to reduce flare light.

As explained above, with the first manufacturing method according tothis embodiment, it is possible to solve the problem of peeling of thelight shielding film 31 and reduce flare light to be equal to or smallerthan a fixed amount.

Therefore, it is possible to obtain a solid-state imaging deviceexcellent in an image quality.

A manufacturing method for the solid-state imaging device according tothe second embodiment is explained with reference to sectional views ofmanufacturing steps in FIGS. 7A to 7D.

As shown in FIG. 7A, the pixel section 12 is formed in the semiconductorsubstrate 11. In the pixel section 12, the plural photoelectricconversion sections 13 that photoelectrically convert incident light togenerate signal charges are formed. Although not shown in the figure, inthe semiconductor substrate 11, a readout section for reading out signalcharges from the photoelectric conversion sections 13 and a chargetransfer section for transferring the signal charges read out by thereadout section are formed on one side of the photoelectric conversionsections 13. A channel stop region for pixel separation is formed on theother side of the photoelectric conversion sections 13.

The first insulating film 21 that covers a transfer electrode (notshown) formed in the charge transfer section is formed on thesemiconductor substrate 11. The metal wirings 22 are formed on the firstinsulating film 21. The second insulating film 23 that covers the metalwirings 22 is formed on the first insulating film 21.

The second insulating film 23 is formed of a silicon nitride film, asilicon oxide nitride film, of a silicon oxide film. More preferably,the silicon nitride film is used. Moisture from the light shielding film31 formed on the second insulating film 23 can be prevented frompenetrating the photoelectric conversion sections 13 by forming thesecond insulating film 23 with an inorganic insulating film such as thesilicon nitride film.

The light shielding film 31 is formed on the second insulating film 23.The light shielding film 31 is formed as explained below.

First, the second light shielding film 34 is formed on the secondinsulating film 23. The second light shielding film 34 is formed of ablack photoresist in thickness smaller than that of the first lightshielding film 33 to be formed later, for example, the thickness equalto or larger than 1.0 μm. In this embodiment, the second light shieldingfilm 34 is formed in the thickness of 0.5 μm. A material of the secondlight shielding film 34 is explained in detail later.

Subsequently, as shown in FIG. 7B, the second light shielding film 34 issubjected to exposure to light, development, and baking to leave thesecond light shielding film 34 above the metal wirings 22 (22S) abovethe pixel section 12 and remove the second light shielding film 34 inother regions. As a result, the second light shielding film 34 is formedabove regions among the photoelectric conversion sections 13.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

As shown in FIG. 7C, the first light shielding film 33 having thicknesslarger than that of the second light shielding film 34 is formed on thesecond insulating film 23 on which the second light shielding film 34 isformed. The first light shielding film 33 is formed of a blackphotoresist in, for example, the thickness equal to or larger than 1.0μm. A material of the first light shielding film 33 is explained indetail later.

As shown in FIG. 7D, the first light shielding film 33 is subjected toexposure to light, development, and baking to form the opening 32 abovethe pixel section 12.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

When the first light shielding film 33 is patterned, since the secondlight shielding film 34 is cured by baking, a pattern shape ismaintained even if exposure, development, and the like is applied to thefirst light shielding film 33.

The black color resist is a negative resist. Since exposure lightattenuates in the black color resist, the black color resist has anundercut sectional shape. Therefore, for example, a pattern having, forexample, pattern dimension width equal to or smaller than 1.5 μm has areduced area of grounding with a substrate and pattern peeling occurs.Therefore, it is desirable to eliminate such a pattern from a mask.

The opening 32 means a space, a side periphery of which is surrounded bya sidewall of the first light shielding film 33 on the pixel section 12.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of blackphotosensitive insulative resin. Consequently, reflection of the lightshielding films is suppressed. Moreover, it is unnecessary to form aresist mask for the patterning. In other words, there is an advantagethat the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

In the second manufacturing method, the first light shielding film 33can be formed in the thickness equal to or larger than 1 μm. Therefore,since light reflected on the large-area metal wirings 22L other thanregions where the photoelectric conversion sections 13 are formed isattenuated, flare light can be suppressed.

Even if the first light shielding film 33 is formed in such thicknessequal to or larger than 1 μm, the second light shielding film 34 formedabove the metal wirings 22 above the pixel section 12 in the opening 32is formed in thickness smaller than that of the first light shieldingfilm 33, for example, the thickness of 0.5 μm. Therefore, a part of theoblique incident light about to be made incident on the photoelectricconversion sections 13, which is blocked by the light shielding filmhaving the thickness in the past, i.e., the light shielding film havingfilm thickness equal to the thickness of the first light shielding film33, can be made incident on the photoelectric conversion sections 13.

Consequently, since an amount of incident light on the photoelectricconversion sections 13 increases, improvement of the sensitivity of thesolid-state imaging device can be realized.

Moreover, since the second light shielding film 34 is formed above themetal wirings 22 above the pixel section 12, the second light shieldingfilm 34 has so-called submicron line width (e.g., equal to or smallerthan 1.5 μm). However, the thickness of the second light shielding film34 is smaller than the thickness of the first light shielding film 34,for example, 1.0 μm and is 0.5 μm in the example explained above.Therefore, even if undercut occurs in the second light shielding film 34in the exposure and development steps and a sectional shape thereofchanges to a so-called reverse taper shape, since an area of groundingwith the second insulating film 23 as the substrate is sufficientlysecured, the problem of peeling is solved.

Since the second light shielding layer 34 is formed above the metalwirings 22 above the pixel section 12 in the opening 32, the metalwirings 22 can be shielded from light. This makes it possible to reduceflare light.

As explained above, with the second manufacturing method according tothis embodiment, it is possible to solve the problem of peeling of thelight shielding film 31 and reduce flare light to be equal to or smallerthan a fixed amount.

Therefore, it is possible to obtain a solid-state imaging deviceexcellent in an image quality.

A manufacturing method for the solid-state imaging device according tothe third embodiment is explained with reference to sectional views ofmanufacturing steps in FIGS. 8A to 8D.

As shown in FIG. 8A, the pixel section 12 is formed in the semiconductorsubstrate 11. In the pixel section 12, the plural photoelectricconversion sections 13 that photoelectrically convert incident light togenerate signal charges are formed. Although not shown in the figure, inthe semiconductor substrate 11, a readout section for reading out signalcharges from the photoelectric conversion sections 13 and a chargetransfer section for transferring the signal charges read out by thereadout section are formed on one side of the photoelectric conversionsections 13. A channel stop region for pixel separation is formed on theother side of the photoelectric conversion sections 13.

The first insulating film 21 that covers a transfer electrode (notshown) formed in the charge transfer section is formed on thesemiconductor substrate 11. The metal wirings 22 are formed on the firstinsulating film 21. The second insulating film 23 that covers the metalwirings 22 is formed on the first insulating film 21.

The second insulating film 23 is formed of a silicon nitride film, asilicon oxide nitride film, of a silicon oxide film. More preferably,the silicon nitride film is used. Moisture from the light shielding film31 formed on the second insulating film 23 can be prevented frompenetrating the photoelectric conversion sections 13 by forming thesecond insulating film 23 with an inorganic insulating film such as thesilicon nitride film.

The light shielding film 31 is formed on the second insulating film 23.The light shielding film 31 is formed as explained below.

First, the second light shielding film 34 is formed on the secondinsulating film 23. The second light shielding film 34 is formed of ablack photoresist in, for example, the thickness equal to or larger than1.0 μm. In this embodiment, the second light shielding film 34 is formedin the thickness of 0.5 μm. A material of the second light shieldingfilm 34 is explained in detail later.

Subsequently, as shown in FIG. 8B, the second light shielding film 34 issubjected to exposure to light, development, and baking to leave thesecond light shielding film 34 above the metal wirings 22 above thepixel section 12 and remove the remaining second light shielding film 34above the pixel section 12 to form the opening 32.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

As shown in FIG. 8C, the first light shielding film 33 is formed on thesecond insulating film 23 on which the second light shielding film 34 isformed. The first light shielding film 33 is formed such that thethickness thereof combined with the thickness of the second lightshielding film 34 prevents the occurrence of flare due to the metalwirings 22L formed around above the pixel section 12. The first lightshielding film 33 is formed in, for example, the thickness equal to orlarger than 1.0 μm. For example, when the second light shielding film 34is formed in the thickness of 0.5 μm, the first light shielding film 33can be formed in thickness equal to the thickness of the second lightshielding film 34.

The first light shielding film 33 is formed of a black photoresist in,for example, the thickness equal to or larger than 1.0 μm. A material ofthe first light shielding film 33 is explained in detail later.

As shown in FIG. 8D, the first light shielding film 33 is subjected toexposure to light, development, and baking to form the opening 32 abovethe pixel section 12.

As an example of a lithography condition for the black color resist, a Gline (436 nm) or an I line (365 nm) is used for exposure light sourcewavelength and exposure time is set to, for example, 1000 ms to 3000 ms.This exposure condition is only an example and appropriately changedaccording to a type of the black color resist.

When the first light shielding film 33 is patterned, since the secondlight shielding film 34 is cured by baking, a pattern shape ismaintained even if exposure, development, and the like is applied to thefirst light shielding film 33.

The black color resist is a negative resist. Since exposure lightattenuates in the black color resist, the black color resist has anundercut sectional shape. Therefore, for example, a pattern having, forexample, pattern dimension width equal to or smaller than 1.5 μm has areduced area of grounding with a substrate and pattern peeling occurs.Therefore, it is desirable to eliminate such a pattern from a mask.

The opening 32 means a space, a side periphery of which is surrounded bya sidewall of the light shielding film 31 formed by the first lightshielding film 33 and the second light shielding film 34 on the pixelsection 12.

The first light shielding film 33 and the second light shielding film 34are formed of insulative resin having light shielding properties. Theinsulative resin having light shielding properties is formed of blackphotosensitive insulative resin. Consequently, reflection of the lightshielding films is suppressed. Moreover, it is unnecessary to form aresist mask for the patterning. In other words, there is an advantagethat the patterning can be directly performed by exposure anddevelopment.

As an example of the insulative resin having light shielding propertiesand the black photosensitive insulative resin, there is a black colorresist.

As a dye containing the black color resist as a black color, forexample, there is a dye obtained by mixing plural pigments of blue andred. There is also a black pigment having low transmittance in a widewavelength (e.g., a wavelength of visible light) band.

A dye with a mixing ratio of a resist and a pigment adjusted such thataverage transmittance is, for example, equal to or higher than 5% andequal to or lower than 40% with respect to, for example, light in arange of wavelength from 400 nm to 700 nm or in a wavelength band ofvisible light is used. If this average transmittance is lower than 5%,since photosensitivity of a photoresist is not sufficiently obtained,the patterning is difficult. If the average transmittance exceeds 40%,since light shielding properties are insufficient, a problem occurs infunctions of the light shielding films. Therefore, the averagetransmittance is set to be equal to or higher than 5% and equal to orlower than 40%.

A negative resist is used as the resist. As an example, an acrylicnegative resist or a polyimide negative resist is used.

In the third manufacturing method, the light shielding film 31 obtainedby combining the first light shielding film 33 and the second lightshielding film 34 can be formed in the thickness equal to or larger than1 μm. Therefore, since light reflected on the large-area metal wirings22L other than regions where the photoelectric conversion sections 13are formed is attenuated, flare light can be suppressed.

Even if the light shielding film 31 obtained by combining the firstlight shielding film 33 and the second light shielding film 34 is formedin such thickness equal to or larger than 1 μm, the second lightshielding film 34 formed above the metal wirings 22 above the pixelsection 12 in the opening 32 can be formed in thickness smaller thanthat of the light shielding film 31, for example, the thickness of 0.5μm. Therefore, a part of the oblique incident light about to be madeincident on the photoelectric conversion sections 13, which is blockedby the light shielding film having the thickness in the past, i.e., thelight shielding film having film thickness equal to the thickness of thelight shielding film 31, can be made incident on the photoelectricconversion sections 13.

Consequently, since an amount of incident light on the photoelectricconversion sections 13 increases, improvement of the sensitivity of thesolid-state imaging device can be realized.

Moreover, since the second light shielding film 34 is formed above themetal wirings 22 above the pixel section 12, the second light shieldingfilm 34 has so-called submicron line width (e.g., equal to or smallerthan 1.5 μm). However, the thickness of the second light shielding film34 is smaller than the thickness of the light shielding film 31, forexample, 1.0 μm. Therefore, even if undercut occurs in the second lightshielding film 34 in the exposure and development steps, since an areaof grounding with the second insulating film 23 as the substrate issufficiently secured, the problem of peeling is solved.

Since the second light shielding layer 34 is formed above regions amongthe photoelectric conversion sections 13 in the opening 32, the metalwirings 22 formed above the pixel section 11 can be shielded from light.This makes it possible to reduce flare light.

As explained above, with the third manufacturing method according tothis embodiment, it is possible to solve the problem of peeling of thesecond light shielding film 34 and reduce flare light to be equal to orsmaller than a fixed amount.

Therefore, it is possible to obtain a solid-state imaging deviceexcellent in an image quality.

In the embodiments explained above, the thickness of the light shieldingfilm 31 around above the pixel section 12 is set to be equal to orlarger than 1.0 μm because, when light is blocked by using the blackcolor resist, the thickness equal to or larger than 1.0 μm is necessaryin order to suppress flare light due to large-area metal wirings.

When the metal wirings 22 formed above the pixel section 12 are shieldedfrom light, it is necessary to set the line width of the light shieldingfilms to be equal to or smaller than 1 μm in order to secure an openingarea of the photoelectric conversion sections 13. Since, in general, thenegative photosensitive resin is used for the black color resist,undercut occurs in a pattern sectional shape after development. In otherwords, the light shielding films have a reverse taper sectional shape.

Therefore, in a pattern having the line width equal to or smaller than 1μm, since an area of grounding with the substrate is reduced, patternpeeling occurs. In order to prevent this problem, if pattern width isset to be equal to or larger 1 μm, since an opening area on thephotoelectric conversion sections 13 is reduced, a part of obliqueincident light is blocked and sensitivity falls.

In order to solve these problems, in the embodiments explained above,the second light shielding film 34 having the thickness smaller thanthat of the light shielding film 31 formed around above the pixelsection 12 is formed above the metal wirings 22 above the pixel section12. Although the second light shielding film 34 has the thicknesssmaller than 1.0 μm, the metal wirings 22 arranged above the regionsamong the photoelectric conversion sections 13 can be shielded fromlight far better than in a solid-state imaging device in which lightshielding films are peeled and not formed at all. Therefore, a largeramount of oblique incident light made incident on the photoelectricconversion sections 13 can be taken in and occurrence of flare due tothe metal wirings 22 can be reduced.

An imaging apparatus according to an embodiment of the present inventionis explained with reference to a block diagram in FIG. 9. The imagingapparatus is an imaging apparatus in which the solid state imagingdevice according to any one of the embodiments is used.

As shown in FIG. 9, an imaging apparatus 200 includes the solid-stateimaging device (no shown) in an imaging unit 201. A focusing opticalsystem 202 that focuses an image is provided on a condensing side of theimaging unit 201. A signal processing unit 203 including a drivingcircuit that drives the imaging unit 201 and a signal processing circuitthat processes a signal, which is photoelectrically-converted by thesolid-state imaging device, into an image is connected to the imagingunit 201. The image signal processed by the image signal processing unit203 can be stored by an image storing unit (not shown). In such animaging apparatus 200, as the solid-state imaging device, thesolid-state imaging device 1, the solid-state imaging device 2, or thesolid-state imaging device 3 explained in the embodiments can be used.

In the imaging apparatus 200 according to this embodiment, since thesolid-state imaging device 1, 2, or 3 according to any one of theembodiments explained above is used, as explained above, the sensitivityof a light-receiving section of each of pixels is sufficiently secured.Therefore, there is an advantage that it is possible to realize pixelcharacteristics, for example, an increase in sensitivity. There is alsoan advantage that flare can be reduced.

The imaging apparatus 200 according to this embodiment is not limited tothe configuration explained above. The present invention can be appliedto an imaging apparatus of any configuration as long as the solid-stateimaging device is used in the imaging apparatus.

The solid-state imaging device 1, 2 or 3 may be formed as one chip ormay be formed as a module having an imaging function in which an imagingunit, a signal processing unit, and an optical system are collectivelypackaged. The present invention can be applied not only to a solid-stateimaging device but also to an imaging apparatus. When the presentinvention is applied to the imaging apparatus, an effect of improvementof an image quality is obtained. The imaging apparatus indicates, forexample, a portable apparatus having a camera and an imaging function.“Imaging” includes not only image pickup during normal cameralphotographing but also fingerprint detection and the like in a broadsense of the imaging.

“Black” in the present invention is ideally black that completelyabsorbs light. However, even if a color is not black that completelyabsorbs light, the color is acceptable if the color looks black or isclose to black, for example, pitch-black, black, a blackish color andthe like specified in color names of object colors (JIS Z 8102: 2001) ofthe Japan Industrial Standard (JIS). Even if a color other than blacksuch as dark brown, dark blue, dark green, or dark blue is mixed in thecolor such as pitch-black, black or a blackish color, the mixed color isacceptable as long as the color as it looks is close to black.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1-3. (canceled)
 4. A manufacturing method for a solid-state imagingdevice comprising the steps of: forming, on a first insulating film thatcovers a pixel section having plural photoelectric conversion sectionsthat are formed in a semiconductor substrate and photoelectricallyconvert incident light to generate signal charges, metal wirings aboveregions among the photoelectric conversion sections and above aperiphery of the pixel section; forming a first light shielding film viaa second insulating film that covers the metal wirings; forming anopening in the first light shielding film above the pixel section;forming a second light shielding film that has thickness smaller thanthat of the first light shielding film on the first light shielding filmincluding the opening; and removing, while leaving the second lightshielding film on the second insulating film above the metal wiringsabove the pixel section, the second light shielding film formed in otherregions.
 5. A manufacturing method for a solid-state imaging deviceaccording to claim 4, wherein the first light shielding film and thesecond light shielding film are formed of insulative resin having lightshielding properties.
 6. A manufacturing method for a solid-stateimaging device according to claim 5, wherein the insulative resin havingthe light shielding properties is formed of black photosensitiveinsulative resin.
 7. A manufacturing method for a solid-state imagingdevice comprising the steps of: forming, on a first insulating film thatcovers a pixel section having plural photoelectric conversion sectionsthat are formed in a semiconductor substrate and photoelectricallyconvert incident light to generate signal charges, metal wirings aboveregions among the photoelectric conversion sections and above aperiphery of the pixel section; forming a second light shielding filmvia a second insulating film that covers the metal wirings; removing,while leaving the second light shielding film on the second insulatingfilm above the metal wirings above the pixel section, the second lightshielding film formed in other regions; forming, on the secondinsulating film, a first light shielding film that covers the secondlight shielding film and has thickness larger than that of the secondlight shielding film; and forming an opening in the first lightshielding film above the pixel section.
 8. A manufacturing method for asolid-state imaging device according to claim 7, wherein the first lightshielding film and the second light shielding film are formed ofinsulative resin having light shielding properties.
 9. A manufacturingmethod for a solid-state imaging device according to claim 8, whereinthe insulative resin having the light shielding properties is formed ofblack photosensitive insulative resin.
 10. A manufacturing method for asolid-state imaging device comprising the steps of: forming, on a firstinsulating film that covers a pixel section having plural photoelectricconversion sections that are formed in a semiconductor substrate andphotoelectrically convert incident light to generate signal charges,metal wirings above regions among the photoelectric conversion sectionsand above a periphery of the pixel section; forming a second lightshielding film via a second insulating film that covers the metalwirings; removing, while leaving the second light shielding film abovethe metal wirings above the pixel section, the remaining second lightshielding film above the pixel section to form an opening; forming, onthe second insulating film, a first light shielding film that covers thesecond light shielding film; and forming an opening in the first lightshielding film above the pixel section.
 11. A manufacturing method for asolid-state imaging device according to claim 10, wherein the firstlight shielding film and the second light shielding film are formed ofinsulative resin having light shielding properties.
 12. A manufacturingmethod for a solid-state imaging device according to claim 11, whereinthe insulative resin having the light shielding properties is formed ofblack photosensitive insulative resin.
 13. (canceled)